Not only could the technique prevent disease in an affected embryo, but the gene would forever be eliminated from the line of descent (the embryo’s children). Pretty great, right?

Yes, but the scary part is that this technique could conceivably be employed to edit any gene. You want taller children? Smarter children? Stronger children? You will be able to have them — for a price.

Human science as we now recognize it began in earnest when Ibn al-Haytham, working in the 11th century, formulated the scientific method: proposing hypotheses and attempting to refute them.

The epistemological tools that al-Haytham advocated took us beyond the superstition, appeals to authority, and baseless speculation that had been the foundation of our so-called knowledge until that point.

Almost every scrap of knowledge we have that is beyond the obvious has been gathered in the thousand years since al-Haythem lived. However, in less than a tenth of that time, the window of human knowledge acquisition will close.

When I lost my belief in God, the near-universal reaction from my Christian friends was to sweep a hand at the marvelous world around us and say, “Where did all this come from, then?” For them, God was the only possible explanation.

As an answer to “Where did all this come from, then?” the multiverse model may seem to be on equal footing with “God did it.” By definition, we cannot reach out and touch other universes to prove they (and therefore a multiverse) exist, much less can we prove that our universe arose from the multiverse by some natural process.

It’s true that we can neither prove that God did it, nor that the multiverse and the laws of physics did it. But as I outlined last time, just because competing explanations are uncertain does not mean they are on equal footing.

Today, we all know that the Moon’s gravity causes the tides, but what did people think before Sir Isaac Newton discovered that gravity is a universal force? I recently heard Jonathan White interviewed on NPR; he is the author of Tides: The Science and Spirit of the Ocean. It turns out that serious people used to hold all manner of fanciful explanations for the tides. Three that I remember from the interview are:

A woman is lifting her skirt and lowering it.

A very large beast in the depths of the ocean is breathing in and out.

The rays of the Moon heat rocks below the ocean, which causes the depths of the ocean to boil. Boiling in the region below the Moon causes the water level to rise.

Of course, these explanations are all wrong but some of them are better attempts at the truth than others. Put yourself in the time when the correct answer was not known. Which explanation would you prefer, and why?

You are standing at a fork in a trolley track, your hand on the lever that can cause the trolley to go one direction or the other. A trolley is coming toward you. If you do not pull the lever, it will go down the fork where five children are on the track. They will surely be killed. (They are tied up, or facing the wrong direction and deaf, or what have you.) If you do pull the lever, their lives will be saved, but your own child, who is immobile on the other fork, will be killed. What is the ethical thing to do?

This is possibly the earliest in a famous series of ethical dilemmas known as trolley problems.

The fun begins when we vary the scenario to tease out people’s moral intuitions. Philosopher Judith Jarvis Thompson posed the most famous version:

As before, a trolley is hurtling down a track towards five people. You are on a bridge under which it will pass, and you can stop it by putting something very heavy in front of it. As it happens, there is a very fat man next to you – your only way to stop the trolley is to push him over the bridge and onto the track, killing him to save five. Should you proceed? [quoted in Wikipedia]

Zoltan Istvan was my favorite presidential candidate in 2016. He toured the country in a bus modeled to look like a coffin, with the message that death is a curable disease.

And it’s not just people on the fringe who are involved in the anti-aging cause. There is a sister company of Google called Calico whose goal is “tackling aging.”

Ray Kurzweil, inventor, senior engineer at Google and holder of 21 honorary doctorates, has written a book called Fantastic Voyage: Live Long Enough to Live Forever. At age 69, he expects technology to improve enough in his lifetime that he will live forever. (In the meantime, he takes extremely good care of himself!)

But hold on a second. While we’re waiting for Istvan, Calico, and Kurzweil succeed, let’s take a moment to ponder the possible dystopian consequences.

In 1814, Pierre-Simon Laplace published A Philosophical Essay on Probabilities. He said that given complete knowledge of the present, one could perfectly predict the future:

We may regard the present state of the universe as the effect of its past and the cause of its future. An intellect which at a certain moment would know all forces that set nature in motion, and all positions of all items of which nature is composed, if this intellect were also vast enough … nothing would be uncertain and the future just like the past would be present before its eyes.

Makes sense, right? If atoms are nothing more than tiny billiard balls bouncing around then, in principle, our lives are as predictable and determined as the activity on a pool table.

A century later, along came quantum mechanics, which showed that the activity of the universe at the smallest scales is probabilistic. Laplace’s Demon (as the all-knowing intellect in the quotation above has come to be known) can’t be so sure after all!

What a relief! There is wiggle room for free will after all! By inserting the lever of our wills at this fulcrum of indeterminacy, we can move the world.